ChromeOS cryptohome should be able to use gaia id as user identifier.

chrome/test/base/testing_profile.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_TEST_BASE_TESTING_PROFILE_H_
 #define CHROME_TEST_BASE_TESTING_PROFILE_H_
 
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 93 matching lines @@
     // Makes the Profile being built a guest profile.
     void SetGuestSession();
 
     // Sets the supervised user ID (which is empty by default). If it is set to
     // a non-empty string, the profile is supervised.
     void SetSupervisedUserId(const std::string& supervised_user_id);
 
     // Sets the PolicyService to be used by this profile.
     void SetPolicyService(scoped_ptr<policy::PolicyService> policy_service);
 
+    // Sets the UserProfileName to be used by this profile.
+    void SetProfileName(const std::string& profile_name);
+
     // Creates the TestingProfile using previously-set settings.
     scoped_ptr<TestingProfile> Build();
 
     // Build an incognito profile, owned by |original_profile|. Note: unless you
     // need to customize the Builder, or access TestingProfile member functions,
     // you can use original_profile->GetOffTheRecordProfile().
     TestingProfile* BuildIncognito(TestingProfile* original_profile);
 
    private:
     // If true, Build() has already been called.
     bool build_called_;
 
     // Various staging variables where values are held until Build() is invoked.
     scoped_ptr<syncable_prefs::PrefServiceSyncable> pref_service_;
 #if defined(ENABLE_EXTENSIONS)
     scoped_refptr<ExtensionSpecialStoragePolicy> extension_policy_;
 #endif
     base::FilePath path_;
     Delegate* delegate_;
     bool guest_session_;
     std::string supervised_user_id_;
     scoped_ptr<policy::PolicyService> policy_service_;
     TestingFactories testing_factories_;
+    std::string profile_name_;
 
     DISALLOW_COPY_AND_ASSIGN(Builder);
   };
 
   // Multi-profile aware constructor that takes the path to a directory managed
   // for this profile. This constructor is meant to be used by
   // TestingProfileManager::CreateTestingProfile. If you need to create multi-
   // profile profiles, use that factory method instead of this directly.
   // Exception: if you need to create multi-profile profiles for testing the
   // ProfileManager, then use the constructor below instead.
   explicit TestingProfile(const base::FilePath& path);
 
   // Multi-profile aware constructor that takes the path to a directory managed
   // for this profile and a delegate. This constructor is meant to be used
   // for unittesting the ProfileManager.
   TestingProfile(const base::FilePath& path, Delegate* delegate);
 
   // Full constructor allowing the setting of all possible instance data.
   // Callers should use Builder::Build() instead of invoking this constructor.
   TestingProfile(const base::FilePath& path,
                  Delegate* delegate,
 #if defined(ENABLE_EXTENSIONS)
                  scoped_refptr<ExtensionSpecialStoragePolicy> extension_policy,
 #endif
                  scoped_ptr<syncable_prefs::PrefServiceSyncable> prefs,
                  TestingProfile* parent,
                  bool guest_session,
                  const std::string& supervised_user_id,
                  scoped_ptr<policy::PolicyService> policy_service,
-                 const TestingFactories& factories);
+                 const TestingFactories& factories,
+                 const std::string& profile_name);
 
   ~TestingProfile() override;
 
   // Creates the favicon service. Consequent calls would recreate the service.
   void CreateFaviconService();
 
   // Creates the history service. If |delete_file| is true, the history file is
   // deleted first, then the HistoryService is created. As TestingProfile
   // deletes the directory containing the files used by HistoryService, this
   // only matters if you're recreating the HistoryService.  If |no_db| is true,
@@ skipping 232 matching lines @@
 
   // Weak pointer to a delegate for indicating that a profile was created.
   Delegate* delegate_;
 
   std::string profile_name_;
 
   scoped_ptr<policy::PolicyService> policy_service_;
 };
 
 #endif  // CHROME_TEST_BASE_TESTING_PROFILE_H_